1. Field of the Invention
Embodiments relate to a coupling body using a Z-pin.
2. Description of the Related Art
To increase the fuel efficiency of a vehicle, active research is being conducted on a method of reducing the weight of a car body by replacing an existing metallic structural part of the vehicle with a polymer composite structural part having an enhanced specific stiffness and specific strength.
A drive shaft may be one of the structural parts to be replaced. The drive shaft transfers a driving force of an engine to a rotating force of wheels, and performs a main task of transferring torque while the shaft is rotating. For example, in a rear-wheel-drive vehicle, whirling-type vibrations may be generated from the rotation of the drive shaft because the drive shaft is long, and thus noise may occur and riding comfort may deteriorate. In addition, in the case of a long drive shaft, a non-productivity issue may occur because two short shafts need to be manufactured and a fixed supporting point needs to be additionally installed halfway between the shafts.
In contrast, using a carbon fiber-reinforced composite material may reduce production and assembling processes because the shafts are manufactured as a single component despite the length. Thus, the carbon fiber-reinforced composite material is known to be economically efficient despite the high price of carbon fiber.
In addition, such a composite drive shaft may make a vehicle more silent because it vibrates less, and may be more fuel efficient because it is lighter in weight. Applying a composite material to a drive shaft is something that is expected to be done for all vehicles in the near future as a measure to comply with regulations on fuel efficiency of a vehicle which are being tightened in developed countries including the United States of America.
A drive shaft has a central axis and connectors at opposite ends. In general, the portion to which a composite material is applied is a portion of the central axis. For the connectors at the ends, various forms are applied based on designs, and a metal material is generally used because the connectors include a portion in a complex form and a portion in which a stress is concentrated.
An existing metallic drive shaft may be used by welding a metallic axis and a metallic connector. Here, in a case of manufacturing the metallic axis as a composite material tube, connecting the tube to the metallic connector may be a core part of the technology. In existing technology, the composite material tube is manufactured through a filament winding method, and thus the tube may be manufactured in a single tube form.
For example, a tool bar for mounting a cutting tool disclosed in Korean Patent Publication No. 10-2012-0029089 includes a tool body and a metal covering. The tool body includes a gripping part, a tool mounting part in which the cutting tool is provided, and a supporting part configured to connect the gripping part and the tool mounting part, and is formed as a composite material. The metal covering includes two ends, and is wound around the outer face of the supporting part covering the outer face of the supporting part. The outer face of the supporting part includes a joint where the edges of the metal covering faces come in contact with each other.